Macintosh IIcx slow clock

[ibook99]

I have a Macintosh IIcx and the time on it is very slow. I did put in a brand-new PRAM battery and the problem still persists. If I replace the Saronix 90R Oscillator with a brand new 31.3344 MHz one will that restore the time functionality?

 

[GRudolf94]

No. You're looking in the wrong spot. The RTC is driven by Y4, and you might have issues with corrosion there, or with the RTC itself. Remember to also check the bottom of the board. Crystals/oscillators seldom fail on their own.

 

[LaPorta]

I had a Classic that had funky time, and it was all cap goo by the RTC/crystal.

 

[ibook99]

Thanks for the info, I was able to fix it. I did replace the 32.768 kHz crystal oscillator with a brand new one and that did not fix the problem. It would take about five seconds for the clock to advance one second.

However when I did a continuity test with my multimeter, I noticed the crystal was not connected with the RTC chip. I noticed a few dark spots on the trace. I flipped the board around and installed a wire to fix the trace (it was easier to do on the other side). Now it keeps perfect time.